Mortising tool



Dec. 16, 1930.

W. M. KNOUREK MoRTIsING TOOL Filed May 19, 1930 l-fateri1t ediY Dec. 16, 1930",-

- JWILLIAMMQKNOUREK, or .fRivERroRnsT,`rLr.rnors1.-

implication filed Vmay' -19,

This invention g of the type which employ a hollow Lchisel and a bit therein, and its principal Objectis to' provide a novel arrangement of parte,

.whereby the usual excessive heating of .the `tool and resulting damage therefrom is elnninated. rt is well knownthat when the ordinary mortising toolV of this type is use d, the chips cut by lthe, bit become wedged 1nk the hollow chisel and the friction which re-V sults therefrom causes thetool to'heat eX- cessively and very frequently` causes the j walls of the chisel to crack, thereby render .ing the tool ineffective. p have been overcome byfornnng serrations or iiutings along the cylindricalface ofthe b1t' which act to oomminute the chips asithey enter the hollow of the chisel, thereby reducing the chips to very small;particles which readily run out of the mortise which is being cut.`

The invention consists, therefore, in a mortising tool of thetype employing a hol` low chisel and therein a bit, in which the bitis formed with serrationsor Vflutings along a portion of its cylindrical face` to provide teeth that comminute the chips formed byV Y the tool. It further consists ina bitY formed with transverse serrations or flutings along" Y a portion of its-length. Y. V

1 features of construction, arrangement and combination of forth and claimed.M

y The invention is clearly illustrated inthe drawing accompanying this lspecification in which l Figure 1 is a side elevation of a mortising tool embodyinga simple .form ofthe present invention;

, Fig. 2 :isa vertical longitudinal section thereof showing the bit in side elevation jline 4-4 of Fig. 1; and Y Fig. 5 is a fragmentary verticall cross sec! ,tion taken on theline Referring to said drawing, the referencev Y Fig. 3 is an end elevation of the tool; l j Fig. l is a horizontal 5 .5 of Fig. A4..

VVcharacter 6 designates a hollow chisel of conventional form providedwith a shank 7 by chuck of a suitable relates vto mort-isingi tools These diiiiculties i It further. consists in the several novel partshereinafter vfully k'set tions lat the` ends thereof.

section taken on kthe 1 hole. ig. 5 shows the corners of the chisel Y cylindrical 95; hole formed by the bit; It willbe observed that the chips formed 1by ythe chisel are cutl Y. and reduced mortisingvg:l machine." y square in cross -section'and is'provi'ded with anelongated 'slot 8 in one of its"` sidewalls through whichV the 4chips arel discharged, and

thewall's at 'the `cuttingendar'e sharpenedito 65 ,form chisel edges as at 9, asis customary. y l'llhe lbitl() extends through `the hollow chisel 6 "and is rotatablyv mounted therein. One end of the bit is'provided with a shank 11 f adapted'tofbe attachedto the revolvingfchuck .60 ofthelnortising machine. TheV hollow chiselv of is bored out/to form a long-bearing for the ,bodyportioni of the fbit to Vrotate in. l

"` Thefbit projects'beyond'the"sharpenedI end Aofthechisel andthedianieteroffits cutting Y n end 12 is made "slightly larger than'theldiameter of itsbody portion so as to ybore 4a holeV substantially of the 'same'diameter as the external ldiameter of they chisel. VAs is: usual, the cutting end "of ythe withfsharp-V ened marginal spurs-'14.7' V 'V'The Vcylindrical face orlhelic'alledge po'rtion of the body of the bit isformedw'itha series 'of serrations or flutingsfliwhich form 75` teeth 16 that act` to* lcut drgbrea-k Vup chipsl that enter 'the chisel, thereby reducing themvv to a comminuted `condition',-wherebyltheyf enter-they grooves of lthebitandare carried' up.anddischarged-*through the'slot 8. The 80 serrations orflutings'may extend from the cutting end of thelbitfthrough only a portion of its length and the remainder of the helical bodyk ofthe bit may be left smoothvso as to bear in the 'bore yof series of `serrations or flutings may be prolvided, `as isjshown 'at .17,

,In operation, the bit'is revolvedv and the chisel ner, kthe bit boring ya round hole in the material and the chisel followingupby cutting outthe cornerportions to form the square entering the materialfbehind `the up by the teeth 16 asthey enter thechise'l p to veryv'small fragments which' readily indt eirwayinto thehelical-grooves 1 097r Vbfi-t is 'formed with 'I0` *sharpened `cutting edgesl and the chisel, ora second y with smooth por-l isreciprocated in the customaryjmany v ly, cannot become wedged between the chisel and the drill. Furthermore, byreason of` -this fact,the parts do not heat to any eX- v Y reduced' toa .'mnimu1n Furthermore; .bec cause of the ,elimination of the `relatively large chips, there is no danger that thechisel K will-become crackedforfbrokeni Mort-ising ltools madein accordanceiwith the present :n d invention last longer land'ldo not require as? 5f, frequentsharpening as theel-*ordinary mortis-,

wing tool employingafhollow chiselan'd` bit."-

of the bit and are carriedup therein and' discharged vthrough the slot 8,. and, consequenttraordinary vdegree and the dangerv of destroying the. temper A.of the .tool is thereby Whilethe teeth l'have beenillustrated as extending in planes running at right angles i torthe axis ofthebit, they may, ofcourse, be-inclinedand may bezof anyfother suitable contour than theone illustrated inthe drawing.- It ifs-.also to be observed :that a'lbit forlnedinaccordance withgthe above descriptionlmayfbe used as a boring bit. separate from: the hollow chisel,` f

Yao

- More or less Variation offthe exact details of construction is possible, without depart- `ng frointhespirit of thiislin'veritionl I desire, therefore, not to limitgnyself lto the exact forni of the construction Y- shown and described, butl intend inv the following `claims,

tog pointl out allot Vthe invention. disclosed herein.' f

Let-tersPatent :Qi Y I Y I claim}as{-rnew,/ and desire 'to secure by chisel,and abitrotatably mount-ed therein,

the cylindrical face of said'bitbeing formed with chip reducingv elements adjacentthe cutting end ofthe bit. p `V 'A 2.'v A- inortising tool 4 comprising aV Ahollow chisel, and abit rotatably .mounted therein, the cylindrical `face ofsaidbit being;4 formed with serrations adjacent fthe cuttingfend' of thejbit;

son

n WILLIAMjM. ifi"riro'irani.y 

